<html>
  <head>
    <title>Now!</title>
    <script type="text/javascript" src="prototype.js"></script>
    <script>
      function update() {
        new Ajax.Updater( 'timeDisplay', 'date.jsp',
          {
            method: 'get'
          }
        );
      }
    </script>
  </head>

  <body>
    <button type="button" onclick="update()">Click me!</button>
    <span id="timeDisplay"/>
  </body>

</html>
